Don't throw away your SXH, it will run fine on a plane...I have 2 planes with them on and both appear to pull better than the std SX....I put it down to the bigger carbs!

A few things you do need to do thought;
1. Crankshaft is shorter. Either replace with the std SX crankshaft or use a spinner nut....that OS produce.
2. The throttle arm sticks way further out, so you may have a problem with cowl clearance, I cut my throttle arm down and re-tapped the threads. You won't have a problem if you use it on an "open bay" plane.

Good luck!